Oil leaking from exhaust

I have a Craftsman push mower with a Briggs engine. The engine use to be easy to start, always on the first try. Lately it hasn't been so easy and sometimes I can feel it pull back when I pull it. Then the other day when I was using it, it started smoking terribly. White smoke. After I stopped it I noticed motor oil leaking from the exhaust. Any ideas? The mower has not been tilted at any great angle.

Re: Oil leaking from exhaust

Hello & WELCOME to LMF...

Check the OIL Level... It is very likely Over Full... Because (while the engine was NOT running), Gasoline has ran into the carb... then into the cylinder ... and then into the crankcase, over filling the oil and causing your problems.
You will need to drain all the oil, put in fresh and fix the needle seat leak in the float bowel, and or inssstall a fuel shut off (in the fuel line) to prevent this in the future... KennyV

Re: Oil leaking from exhaust

I agree with Kenny, it sounds like your carburetor is letting too much fuel through and it is seeping into the crankcase which will cause an oil/fuel mixture to get into the combustion chamber and if it can't all be burnt (as it won't be able to at that rate) it'll go through the exhaust valve as liquid and then out the exhaust.

Get it fixed ASAP, as running a mower with fuel in the oil won't be doing the bearings or piston any good, and the oil/fuel coming out of the exhaust is a fire hazard.

Re: Oil leaking from exhaust

Today I checked the oil and it was a little high. I don't know what real high would even look like on the dip stick I dont guess but it looked to be about 3/16 past the full mark. Thats what like 4- 5mm.
I drained the oil and put in some more. Then checked the air filter. No oil on it but was very dirty so I changed it. Then I pulled out it spark plug. It was covered with oil, so I changed it too.
I started it and it was still smoking like crazy, so I stopped it. I started it a few more times after that and it seemed like each time it was getting a little better, then the last time there was no noticeable amount. I think it just needs to burn up all the oil that is in there. Is there anything I could pour into the fuel system that would help it?

Re: Oil leaking from exhaust

Originally Posted by Cdy291

Today I checked the oil and it was a little high. I don't know what real high would even look like on the dip stick I dont guess but it looked to be about 3/16 past the full mark. Thats what like 4- 5mm.
I drained the oil and put in some more. Then checked the air filter. No oil on it but was very dirty so I changed it. Then I pulled out it spark plug. It was covered with oil, so I changed it too.
I started it and it was still smoking like crazy, so I stopped it. I started it a few more times after that and it seemed like each time it was getting a little better, then the last time there was no noticeable amount. I think it just needs to burn up all the oil that is in there. Is there anything I could pour into the fuel system that would help it?

You could try some of that fuel system cleaner additive you can buy for vehicles, but I'd suggest just running it on pure gasoline and let it naturally clean itself out.

Hopefully it will stop giving you problems now, but if it persists, just come back here and we'll help you!

Re: Oil leaking from exhaust

Originally Posted by Cdy291

Today I checked the oil and it was a little high. I don't know what real high would even look like on the dip stick I dont guess but it looked to be about 3/16 past the full mark. Thats what like 4- 5mm.
I drained the oil and put in some more. Then checked the air filter. No oil on it but was very dirty so I changed it. Then I pulled out it spark plug. It was covered with oil, so I changed it too.
I started it and it was still smoking like crazy, so I stopped it. I started it a few more times after that and it seemed like each time it was getting a little better, then the last time there was no noticeable amount. I think it just needs to burn up all the oil that is in there. Is there anything I could pour into the fuel system that would help it?

Maybe a shot of Sea-Foam, per recommended mixing instructions, but otherwise, as you've discovered, it'll take some time to burn off the residue. Keep a close eye on your oil level, your carb may need some attention.

Re: Oil leaking from exhaust

Prior to all this, was it using oil extensively? Had you added any just prior to this happening?
and he's right, exhaust seal......no fun...I'd rather unbolt the blade and engine and replace with a good on off a 25 dollar mower.....but that's me........

~ Live everyday as thou your last. For one day, your sure to be right ~

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